Hey there! I’ve actually written a DK guide in the past, due to this exact question!
So! Something to keep in mind is, “Generation.” Is more of a fanon thing for us Ebon Blade RPers. So, none of it is actually set in stone from Blizzard. I’ll copy and paste this from my own guide.
FIRST GENERATION [Year 5]
Made from the corpses of slain Knights of Stormwind during the last battle in the First War. Gul’dan created these soldiers for Orgrim Doomhammer. The souls of deceased warlocks of the Shadow Council were placed into these fallen humans to create the first Death Knights.These were not like the Knights you see today: “Unlike modern death knights of the Scourge, these ghoulish fiends were not battle hardened warriors; they were insidious necromancers who possessed superior intellect and tremendous magical power.” Most of these Death Knights were destroyed during and after the Second War, or transformed into liches. [Year 4-8].
SECOND GENERATION [Approximately Year 20-21]
A small band of renegade paladins after being persecuted by the general populace who believed they were infected with the plague when attempting to help. They set off to travel north to find the source of the plague. During this, they succumbed to “bitter hatred”. Once they reached Ner’zhul’s fortress, the Lich King (Ner’zhul) offered them “untold power” in exchange for their loyalty. They accepted such. They retained their humanity, but their souls were twisted and bound to the will of the Frozen Throne for all time. They were bestowed black vampiric runeblades, shadowy steeds and served as the Scourge’s mightiest generals at the time
DEBATED SECOND GEN: [Year 20-22]
“The rest were primarily made up of other fallen warriors or paladins whose souls were twisted and bound to the will of the Frozen ” It’s uncertain if “Second Generation” also includes members who were also raised in different situations around that time such as: Thassarian and Koltira Deathweaver. It is up to player choice if said Knights are Second or Third Generation.
NOTE: It is player choice if 2nd gen also applies to those who were not given vampric runeblades. However, in my opinion, “Generation” implies time. So I personally consider Paladins/Warriors risen in that time who weren’t Silver Hand Second generation.
THIRD GENERATION: [Year 27]
Bound to the will of the Lich King Arthas, these Death Knights are more popularly known. Risen in bulk as former heroes in life, they faced intense challenges which if failed resulted in execution. The majority of lore for Third Generations you can find by simply completing the Death Knight starting zone questline. The majority of Death Knights belong to the Third Generation.
FOURTH GENERATION: [Year 32-33]
There’s very limited lore regarding Fourth Generation currently. It’s assumed they’re risen similar, if not identical to Third Generation. There’s nothing confirming if they are, or aren’t bound to the Throne, but they do swear fealty. It is unsure if they suffer from similar hunger and/or emotional absence. In my opinion roleplaying them similar to Third Generation is probably the most reasonable method until more lore is made available.
If you ever need more DK lore help, or if you ever wanna discuss it. Feel free to add my discord: Basic Glitch#8653